SOLUTION: I was reviewing the quadratic equation y=-3x^2-6x-5 for problem #252391. I had already found that if x=0 then y=-5. I'm having trouble creating a table of ordered pairs to use in

Algebra ->  Graphs -> SOLUTION: I was reviewing the quadratic equation y=-3x^2-6x-5 for problem #252391. I had already found that if x=0 then y=-5. I'm having trouble creating a table of ordered pairs to use in      Log On


   

Question 307412: I was reviewing the quadratic equation y=-3x^2-6x-5 for problem #252391. I had already found that if x=0 then y=-5. I'm having trouble creating a table of ordered pairs to use in graphing using excel. I would think I need at least 3 sets of ordered pairs to be able to do this. Can someone show me what other pairs to use and how they were figured. I want to understand this, I'm not very good at these equations. Thanks!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
To find ordered pairs, just plug in arbitrary x values to find their corresponding y values.


If x=2, then y=-3%282%29%5E2-6%282%29-5=-3%284%29-6%282%29-5=-12-12-5=-29 giving you the ordered pair (2,-29)


If x=1, then y=-3%281%29%5E2-6%281%29-5=-3%281%29-6%281%29-5=-3-6-5=-14 giving you the ordered pair (1,-14)


If x=0, then y=-3%280%29%5E2-6%280%29-5=-3%280%29-6%280%29-5=0-0-5=-5 giving you the ordered pair (0,-5)


If x=-1, then y=-3%28-1%29%5E2-6%28-1%29-5=-3%281%29-6%28-1%29-5=-3%2B6-5=-2 giving you the ordered pair (-1,-2)


If x=-2, then y=-3%28-2%29%5E2-6%28-2%29-5=-3%284%29-6%28-2%29-5=-12%2B12-5=-5 giving you the ordered pair (-2,-5)



If x=-3, then y=-3%28-3%29%5E2-6%28-3%29-5=-3%289%29-6%28-3%29-5=-27%2B18-5=-14 giving you the ordered pair (-3,-14)


If x=-4, then y=-3%28-4%29%5E2-6%28-4%29-5=-3%2816%29-6%28-4%29-5=-48%2B24-5=-29 giving you the ordered pair (-4,-29)



Once you have your ordered pairs, which are essentially points, plot them on a grid and draw a parabola through them.